ABBOTT PARK, Ill., and WATERTOWN, Mass., March 2, 2010 – Abbott and Enanta Pharmaceuticals announced today the advancement of their Hepatitis C (HCV) collaboration into Phase 2 clinical trials. The trial will evaluate three HCV antiviral agents, including the investigational protease inhibitor ABT-450, part of the Abbott- Enanta collaboration, and polymerase inhibitors ABT-333 and ABT-072 currently being developed exclusively by Abbott. Each antiviral agent will be dosed individually in combination with the current standard of care (SOC).

ABT-450 was discovered as part of an alliance between Abbott and Enanta. ABT-333 and ABT-072, both discovered internally at Abbott, are part of the company’s ongoing non-nucleoside polymerase inhibitor development program.

"Our scientists are working diligently to advance the treatment of Hepatitis C, which is a serious global epidemic that affects 170 million people worldwide,” said John M. Leonard, M.D., senior vice president, Global Pharmaceutical Research and Development, Abbott. “As a global leader in the development of antiviral therapies, we are focused on building an industry-leading pipeline for the treatment of HCV and are well-positioned to explore multiple potent and new classes of HCV therapies that hold promise for patients.”

While significant progress has been made in HCV treatment, there are limitations in efficacy and safety for the current standard of care. An extended duration of treatment (24 or 48 week course of a combination of pegylated alpha interferon and ribavirin) still results in a less-than 50% cure rate in those with HCV genotype 1. Additionally, the side-effects from interferon therapy can be highly problematic, often including depression and flu-like symptoms.

"Initiating Phase 2 is a key step in advancing our HCV collaboration,” said Jay R. Luly, Ph.D., president and CEO of Enanta Pharmaceuticals. "We look forward to working with Abbott to advance our shared vision of creating breakthrough treatments for HCV infection."

The objectives of the Phase 2 study are to assess the safety, tolerability, pharmacokinetics, and antiviral activity of multiple dose strengths of ABT-450 or ABT- 333 or ABT-072, each dosed individually in treatment-naïve adults infected with HCV genotype 1, the most common and difficult to treat form of the infection in the developed world. Initial antiviral activity will be evaluated via a 3-day monotherapy period. Subsequently, each antiviral agent will be administered with pegIFN/RBV (SOC) for 12-weeks, followed by treatment with SOC alone for an additional 36- weeks. Participants will then be monitored for sustained virologic response (SVR).

About Hepatitis C Virus

Hepatitis C is a liver disease affecting over 170 million people worldwide. The virus is spread through direct contact with the blood of an infected person. Hepatitis C increases a person’s risk of developing chronic liver disease, cirrhosis, liver cancer and death. Liver disease associated with HCV infection is growing rapidly, and current therapies only provide sustained benefit in about half of patients with the genotype1 form of the virus. Specifically targeted antiviral therapies for HCV, such as NS3/4a protease inhibitors and non-nucleoside polymerase inhibitors, may have the potential to increase the proportion of patients in whom the virus can be eradicated.

About Enanta

Enanta Pharmaceuticals is a research and development company that uses its novel chemistry approach and drug discovery capabilities to create best in class small molecule drugs in the infectious disease field. Enanta is developing novel protease, NS5A, polymerase, and cyclophilin-based inhibitors targeted against the Hepatitis C virus (HCV). Additionally, the Company has created a new class of macrolide antibiotics, called Bicyclolides, which overcomes bacterial resistance. Antibacterial focus areas include superbugs, respiratory tract infections, and intravenous and oral treatments for hospital and community MRSA. Enanta is a privately held company headquartered in Watertown, MA. Enanta's news releases and other information are available on the company's web site at www.enanta.com.

About Abbott

Abbott is a global, broad-based health care company devoted to the discovery, development, manufacture and marketing of pharmaceuticals and medical products, including nutritionals, devices and diagnostics. The company employs approximately 83,000 people and markets its products in more than 130 countries.

Abbott's news releases and other information are available on the company's web site at www.abbott.com.